How to Trust an App on iPhone – Complete Guide

If you’re installing third-party apps on your iPhone or iPad, you may see the “Untrusted Developer” error. This usually happens when an app is downloaded from a source other than the App Store, like Scarlet iOS.

Apple blocks apps from unknown developers to protect users from potential security threats. However, if you’re using a trusted alternative store like Scarlet or AltStore, you can manually approve the app to use it without issues.

In this guide, we’ll walk you through the process of trusting a third-party app on your iPhone, discuss common issues, and provide expert-backed solutions.

Why Does iPhone Ask Users to Trust Apps?

Apple’s iOS security policies restrict the installation of apps from unknown sources to prevent malware and unauthorized access to user data. When you install an app from a third-party source like Scarlet iOS, iOS blocks it until you manually approve the developer.

Is It Safe to Trust Third-Party Apps?

• Apps from well-known third-party stores like Scarlet or AltStore are generally safe if downloaded from their official websites.
• However, be careful with unauthorized sources, as some apps may contain malware, spyware, or other security vulnerabilities.
• Always check for community feedback and developer transparency before trusting an external app.

How to Trust an App on iPhone (Including Scarlet iOS)

Follow these steps to manually trust a third-party app:

Step 1: Install the App Correctly

• Download Scarlet iOS or any other app only from its official website to avoid security risks.
• Avoid downloading IPA files from unverified sources, as they may be modified with malicious code.

Step 2: Try to Open the App

• After installation, try opening Scarlet or any third-party app.
• You’ll see the following error message:
  “Untrusted Enterprise Developer”
  This means iOS does not recognize the developer.

Step 3: Navigate to Settings

• Open Settings > General
• Scroll down and tap on VPN & Device Management (or Profiles & Device Management in older iOS versions)

Step 4: Trust the Developer Profile

• Under Enterprise App, locate the developer profile linked to the app.
• Tap on the developer name and select Trust [Developer Name].
• Confirm your selection by tapping Trust again in the pop-up notification.

Step 5: Open the App Again

• Now, the app should open and function without any issues.
• If the app still does not work, refer to the troubleshooting section below.

Common Issues & Fixes While Trusting an App (Including Scarlet iOS)

1. App Not Opening (Crashing Issue)

Cause: Apple regularly revokes enterprise certificates, preventing unauthorized apps from running.

Solution:

• Reinstall the app from the official website.
• Use an anti-revoke VPN to prevent Apple from detecting and blocking the certificate.
• Try AltStore or Sideloadly as alternative installation methods.

2. “Unable to Verify App” Error

Cause: Unstable internet connection or revoked certificate.

Solution:

• Ensure WiFi or mobile data is enabled.
• Disable any connected VPN and try again.
• Reinstall the app and re-trust the developer.

3. “Trust” Option Not Showing in Settings

Cause: Software glitches or outdated iOS versions.

Solution:

• Restart your iPhone and check again.
• Update to the latest iOS version.
• Reinstall the app and verify the developer profile.

4. App Stops Working After a Few Days

Cause: Apple has revoked the app’s certificate.

Solution:

• Download the latest version of the app from the official website.
• Use AltStore or Sideloadly for installation.
• Install anti-revoke tools to prevent Apple from blocking the certificate.

For additional guidance, visit check how to install Scarlet with custom certificate and how to install eSign.

FAQs

Yes, but only for authorized apps. Downloading pirated or modified software may violate Apple’s terms and legal regulations.

How Can I Avoid Revoked Certificates?

• Use Sideloading methods like AltStore or Sideloadly.
• Avoid public enterprise-signed apps, as they are often revoked by Apple.
• Follow official sources and forums for updated installation guides.

Conclusion

Trusting a third-party app on an iPhone is straightforward if you follow the correct steps and download only from reliable sources. However, always prioritize security and avoid unverified apps that may pose risks.

If you encounter issues, alternative methods like AltStore or Sideloadly can help you install third-party apps securely. Staying informed and taking necessary precautions when sideloading apps will help keep your iPhone safe from potential security threats.